You are minding your own business when suddenly one of your system splats out something like "INFO: rcu_bh_state detected stalls on CPUs/tasks: { 3 5 } (detected by 2, 2502 jiffies)". Whatever does this RCU CPU stall warning mean and what can you do about it? That is, other than simply beating your head against Documentation/RCU/stallwarn.txt?

This talk will look at a few representative RCU CPU stall warning messages and show how they can be decoded into real information that can help you find otherwise silent hangs the easy way. Or at least an easier way!